lightning hit tree
There isn't anything special for you to do for the tree, unfortunately. You should definitely keep it well watered because you don't want to add any extra stresses to it.
Here's a good article on lightning strikes and trees: https://www.extension.purdue.edu/extmedia/FNR/FNR-FAQ-9-W.pdf
Unfortunately, the best advice is to take a wait and see approach and try to prevent other stresses to the tree.